Fast 3D radiography with multiple pulsed x-ray sources by deflecting tube electron beam using electro-magnetic field

ABSTRACT

An X-ray imaging system using multiple pulsed X-ray sources to perform highly efficient and ultrafast 3D radiography is presented. There are multiple pulsed X-ray sources mounted on a structure in motion to form an array of sources. The multiple X-ray sources move simultaneously relative to an object on a pre-defined arc track at a constant speed as a group. Electron beam inside each individual X-ray tube is deflected by magnetic or electrical field to move focal spot a small distance. When focal spot of an X-ray tube beam has a speed that is equal to group speed but with opposite moving direction, the X-ray source and X-ray flat panel detector are activated through an external exposure control unit so that source tube stay momentarily standstill equivalently. 3D scan can cover much wider sweep angle in much shorter time and image analysis can also be done in real-time.

The present invention claims priority to Provisional Application Ser.No. 63/182,426 filed on Apr. 30, 2021; 63/226,508 filed Jul. 28, 2021;63/170,288 filed Apr. 2 2021, 63/175,952 filed Apr. 16, 2021, 63/194,071filed May 27, 2021; 63/188,919 filed May 14, 2021; 63/225,194 filed Jul.23, 2021; 63/209,498 filed Jun. 11, 2021; 63/214,913 filed Jun. 25,2021; 63/220,924 filed Jul. 12, 2021; 63/222,847 filed Jul. 16, 2021;63/224,521 filed Jul. 22, 2021; and U.S. application Ser. No. 17/149,133filed Jan. 24, 2021, which in turn claims priority to Provisional Ser.62/967,325 filed Jan. 29, 2020, the content of which is incorporated byreference.

FIELD OF THE INVENTION

This patent specification is in the field of 3D X-ray radiographysystems and methods and particularly to using pulsed X-ray sources andX-ray digital flat panel detector.

BACKGROUND

Digital Tomosynthesis (DIS) performs high-resolution limited-angletomography at radiation dose levels comparable with conventionalradiography.

When tomosynthesis is performed, the X-ray source would need to move inan arc around a scanned object. While the X-ray source moves around theobject, a series of X-ray images are acquired at different angles.

The collected data set permits the reconstruction of parallel planes.Each plane is in focus, and those that are out-of-plane tissue imagesare blurred. Usually, a wider sweep angle would generate more dataprojections and result in better 3D resolution, but it takes longer. Inaddition, data processing is manufacturer-specific because differentreconstruction algorithms might be used.

These kinds of digital tomosynthesis systems and methods can be appliedto X-ray 3D radiography applications such as X-ray mammography, X-ray 3Dchest diagnosis system for COVID, X-ray 3D Non-Destructive Test (NDT)system, and X-ray 3D security inspection system.

There are prior arts with the single X-ray source and single flat panelto perform X-ray 3D radiography. However, there are disadvantages amongprior arts.

The main disadvantage is that a single X-ray source takes a very longtime to acquire good data projections. It is true for both continuousmode and step-and-shoot mode. In continuous mode, the X-ray source emitsX-ray while it is moving; in step-and-shoot mode, the X-ray source movesto a location, stops and emits X-ray, and continues moving to the nextlocation.

Although all patients hope X-ray imaging could be done as fast aspossible, there is a minimum X-ray source travel sweep anglerequirement. If the sweep angle is too small so that the X-ray sourcecan travel less and the total time needed is less, then the system willhave smaller numbers of data projections. The smaller number of dataprojections would result in lower depth resolution and loss of detailsperception. On the other hand, if the sweep angle needs to be largeenough for good data projections for better 3D resolution, then a singleX-ray source may mechanically travel too long that patients will feeluncomfortable and cannot hold breast standstill anymore. In some cases,a 50-degree sweep would take as long as about half a minute.

The second disadvantage is that it is difficult to do real-timereconstruction because the whole thing is slow. Usually, prior art takestens of seconds to finish sweeping.

A Fast 3D Radiography with multiple pulsed X-ray sources by deflectingX-ray tube electron beam using either electrical field or magnetic fieldis proposed in the current invention. It utilizes motion control,multiple pulsed X-ray sources, and deflecting electrical field ormagnetic field.

The mechanism of deflecting electron beam by the magnetic field issimilar to using magnetic deflection yoke at cathode ray tubes. However,this invention is to deflect the electron beam only horizontally in onedirection.

Another way of deflecting an electron beam is to put one pair ofelectrodes inside or outside the X-ray tube after the electron gunstructure. Electrostatic deflection is more common for high frequenciesthan driving the large inductance of a deflection magnetic yoke.

Compared with electrostatic deflection, magnetic deflection has fewerobstructions at the X-ray tube, allowing for a larger-diameter electronbeam.

SUMMARY

In a first aspect, a system to provide fast 3D radiography usingmultiple pulsed X-ray sources in motion with a primary motor stagemoving freely on an arc rail with a predetermined shape; a primary motorthat engages with said primary motor stage and controls a speed of theprimary motor stage; a plurality of X-ray sources each moved on theprimary motor stage; a supporting frame structure that provides housingfor the primary motor stage; a flat panel detector to receive X-rayimaging data; a deflection plate to produce electrical field or amagnetic coil yoke to produce a magnetic field at X-ray tube electronbeam.

In a second aspect, a method of fast 3D radiography using multiplepulsed X-ray sources in motion includes positioning a primary motorstage to a predetermined initial location; sweeping the primary motorstage at a predetermined constant speed by said primary motor;deflecting X-ray tube electron beam with a predetermined sequence byapplying a voltage to plate or by applying current to magnetic coil;electrically activating an X-ray source and an X-ray flat panel detectorwhen an X-ray tube focal spot moves in the opposite direction to that ofthe primary motor stage and at a selected speed of the primary motorstage; and acquiring image data from the X-ray source with a flat panel.

In another aspect, an X-ray imaging system using multiple pulsed X-raysources in motion to perform ultrafast, highly efficient 3D radiographyis presented. In the system, multiple pulsed X-ray sources are mountedon a structure in motion to form an array of the source. The multipleX-ray sources move simultaneously around an object on a pre-definedtrack at a constant speed of a group. X-ray tube focal spot at eachX-ray source can also move rapidly around its static position of a smalldistance by deflection electrical field or deflection magnetic field.When an X-ray tube focal spot on an individual X-ray source has a speedequal to group speed but an opposite moving direction, the individualX-ray source is triggered through an external exposure control unit.This arrangement allows the X-ray source to stay relatively standstillduring the X-ray pulse trigger exposure duration. Multiple X-ray sourcesresult in a much-reduced source travel distance for individual X-raysources. X-ray receptor is an X-ray flat panel detector. 3D radiographyimage projection data can be acquired with an overall much wider sweepin a much shorter time period, and image analysis can also be done inreal-time while the scan goes.

In another aspect, an X-ray imaging system using multiple pulsed X-raysources in motion to perform highly efficient and ultrafast 3Dradiography includes multiple pulsed X-ray sources mounted on astructure in motion to form an array of sources. The multiple X-raysources move simultaneously relative to an object on a pre-defined arctrack at a constant speed as a group. Focal spot at each individualX-ray source can also move rapidly around its static position at a smalldistance. When X-ray tube focal spot of an individual X-ray source has aspeed that is equal to group speed, but with opposite moving direction,the individual X-ray source and X-ray detector are activated through anexternal exposure control unit. This arrangement allows the X-ray sourceto stay relatively standstill during the X-ray source activation andX-ray detector exposure, X-ray receptor is an X-ray flat panel detector.Multiple X-ray source in motion operation results in a much-reducedsource tube travel distance for individual X-ray sources. 3D radiographyimage data can be acquired with an overall much wider sweep angle in amuch shorter time, and image analysis can also be done in real-timewhile the scan goes.

In implementations, the X-ray can also be randomly activated from one ofany sources in the array using a random-firing scheme. Results of eachand accumulated analysis determines the next X-ray source and exposurecondition. 3D X-ray radiography images are reconstructed based on eachimage with an angled geometry of X-ray exposure source. Much broaderapplications include 3D mammography or Tomosynthesis, chest 3Dradiography for COVID or fast 3D NDT, fast 3D X-ray security inspection.

Advantages of the above systems may include one or more of thefollowing. The various embodiment of multiple X-ray sources in motion isused in a novel ultrafast 3D radiography system.

The first advantage is that system overall is several times faster. EachX-ray source would only need to mechanically travel a small fraction ofthe whole distance in an arc trajectory. It greatly reduces the amountof data acquisition time that is needed fora patient at the X-raydiagnosis machine.

The second advantage is that image analysis can also be done inreal-time as the scan goes. Judgment on the images taken will have animpact on the X-ray source focal spot position for the next shot. Thereis no need to wait until the finish of the whole image acquisition to dolayered image reconstruction.

The third advantage is that acquisition of high resolution, and highcontrast images are possible due to reduction of motion artifacts. EachX-ray source has its electrical field or magnetic field that can movethe X-ray source focal spot around its origin. The composition of focalspot moving speed and track speed leads to the relative standstillposition of the X-ray sources at the moment the individual X-ray sourceis activated.

The fourth advantage is that system can go a much wider sweep to acquiremore data projections while being faster. More data projections meanbetter image construction that would lead to a reduced misdiagnosisrate.

The fifth advantage is that because of a wider angle and faster imagingacquisition, and it is possible to add time components to 3D spatialimaging to form 4D imaging data set.

The present invention has been described in terms of the preferredembodiment, and it is recognized that equivalents, alternatives, andmodifications, aside from those expressly stated, are possible andwithin the scope of the appending claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an ultrafast 3D digital radiography system withmultiple X-ray source tubes in motion using deflection electrical field.

FIG. 2 illustrates part of an ultrafast 3D digital radiography systemwith X-ray source tube in motion using deflection magnetic field.

FIG. 3 illustrates that a five-X-ray-source system that takes 25 sets ofprojection data by each X-ray source traveling only one-fifth of thetotal distance.

FIG. 4 illustrates an exemplary deflection of electron beam in an X-raytube by a pair of magnetic coils when current flows through the coils.

FIG. 5 illustrates an exemplary deflection of electron beam in an X-raytube by a pair of electric plates through a voltage difference.

DETAILED DESCRIPTION

The following discussion describes in detail one embodiment of theinvention (and several variations of that embodiment). However, thisdiscussion should not be construed as limiting the invention to thoseparticular embodiments. Practitioners skilled in the art will recognizenumerous other embodiments as well. For definition of the complete scopeof the invention, the reader is directed to appended claims.

Thus, for example, it will be appreciated by those of ordinary skill inthe art that the diagrams, schematics, illustrations, and such asrepresent conceptual views or processes illustrating systems and methodsembodying this invention. The functions of the various elements shown inthe figures may be provided through the use of dedicated hardware andhardware capable of executing associated software. Similarly, anyswitches shown in the figures are conceptual only. Their function may becarried out through the operation of program logic, through dedicatedlogic, through the interaction of program control and dedicated logic,or even manually, the particular technique being selectable by theentity implementing this invention. Those of ordinary skill in the artfurther understand that the exemplary hardware, software, processes,methods, and operating systems described herein are for illustrativepurposes and, thus, are not intended to be limited to any particularnamed manufacturer.

A novel ultrafast 3D digital imaging system with multi pulsed X-raysources by deflecting tube electron beam using electrical field is shownin FIG. 1 . It comprises a primary motor 3 engaged with a primary motorstage 4, multiple X-ray tubes 6, each in X-ray source tube housing 5 anda pair of deflection electrical plates 7 on each side of each tube 6.The X-ray source tube housings 5 are mounted on a supporting framestructure 2, all of which move together on the primary motor stage 4.

By applying a voltage difference at the electrical deflection plate 7,an electrical field will be created between the electrical deflectionplates 7 as shown in FIG. 5 . The strength of the electrical fieldvaries upon the voltage applied. The deflection of the electron beam ofthe X-ray tube can be achieved by using a deflection magnetic field asshown in FIG. 4 . A primary motor 3 mechanically engages with a primarymotor stage 4 to control the speed of the primary motor stage 4. X-raysources move in arcs at the same speed as the primary motor stage 4,with the primary motor 3 being on one side of the primary motor stage 4.A supporting frame structure 2 provides housing for the primary motorstage 4 and X-ray sources. A flat panel detector 1 receives X-rayimaging data. A pair of deflection plates 7 or a pair of magnetic coils8 yoke produces an electrical field or a magnetic field at the X-raytube electron beam 9.

The multiple pulsed X-ray sources or X-ray tubes 6 are mounted on theprimary motor stage 4 to form an array of sources. The multiple X-raysources move simultaneously relative to an object on a pre-defined arctrack at a constant speed as a group. Electron beam 9 inside eachindividual X-ray tube can be deflected by magnetic or electrical fieldto move focal spot a small distance. When the focal spot of an X-raytube beam has a speed that is equal to group speed but with oppositemoving direction, the X-ray tube 6 and X-ray flat panel detector 1 areactivated through an external exposure control unit so that source tubestay momentarily standstill equivalently. With the multiple sources orX-ray tubes 6 working parallel, the system only moves a fraction of thedistance that a single tube system has to move. As a result, the 3D scancan cover much wider sweep angle in much shorter time and image analysiscan also be done in real-time.

To power the structure in motion, the primary motor 3 engages primarymotor stage 4 by gears. Primary motor 3 can move primary motor stage 4along a rigid rail at a predetermined constant speed. By applying avoltage to a pair of deflection electrical plates 7 at X-ray tube 6, theelectron can be deflected before X-ray tube electrons reach the X-raytube target 11. By fine-tuning voltage, the electron focal spot can movealong the direction of primary motion stage 4. When focal spot speed isequal to the primary motion stage 4 and has an opposite direction, thenX-ray tube 6 and X-ray flat panel detector 1 are triggered. At thistrigger moment, X-ray tube 6 and X-ray detector 1 actually have arelative standstill position.

The primary motion stage 4 with the X-ray source(s) is moved on an arcrail with a predetermined shape, and the X-ray source(s) is moved onsaid primary motion stage 4 at a constant speed by said primary motor 3.Multiple X-ray sources are mounted on said primary motion stage 4 in theform of an array of sources. The multiple X-ray sources movesimultaneously around an object on a pre-defined track at a constantspeed as a group. The focal spot of the X-ray source can also moverapidly around its static position of a small distance. When an X-raytube focal spot on an individual X-ray source has a speed equal to groupspeed but an opposite moving direction, the respective X-ray source istriggered through an external exposure control unit. This arrangementallows the X-ray source to stay relatively standstill during the X-raypulse trigger exposure duration. Multiple X-ray sources result in amuch-reduced source travel distance for individual X-ray sources. A flatpanel detector 1 is placed on a supporting frame structure to receiveX-ray imaging data. A pair of deflection plate 7 or a magnetic coil 8yoke is positioned to produce an electrical field or a magnetic coil atan X-ray tube electron beam 9.

Multiple X-ray tubes 6 in an array and the detector will be mechanicallymoved in a predetermined arc track by a primary motor stage 4. A set ofmultiple X-ray tubes can be connected to a primary motor stage 4 via arack and pinion type mechanical structure or fixed on a plurality ofbases with a fixed distance between each other. The X-ray tube focalspot is deflected in one direction and opposite direction by electricfield or magnetic field. While moving on the arc track, individual X-raytubes would move rapidly around their static position by a deflectingelectric field or magnetic field. X-ray sources from one of the sourcescan be randomly activated through the control unit, in which 3Dradiography image data acquisition and image analysis can be made inreal-time while the scan goes. A preferred method to trigger multiplepulsed X-ray sources in motion includes positioning a primary motorstage 4 to a predetermined initial location; sweeping the primary motorstage at a predetermined constant speed by said primary motor 3;deflecting X-ray tube electron beam 9 with a predetermined sequence byapplying a voltage to plate or by applying current to magnetic coil;electrically activating an X-ray source and a flat panel detector 1 whenan X-ray tube focal spot moves in an opposite direction to that of theprimary motor stage 4 and at a selected speed of the primary motor stage4; and acquiring image data from an X-ray flat panel detector 1.

X-ray source tube housing 5 is pivotally mounted on an axis parallel tothe X-ray source mounting plate and coupled to a rotation drivingmechanism that causes the X-ray source tube housing to rotate around anaxis parallel to the X-ray source mounting plate. The angle of rotationis designated by an angle “β” in this application. The amount of angleof rotation can be set by the user based on specific requirements. In anexemplary embodiment, the angle of rotation is about 12.5 degrees. Asingle rotation driver couples the X-ray source tube housing 5 to ageared motor for rotating X-ray source tube housing 5. The rotationdriving mechanism comprises two pairs of pulleys and, wherein each pairof pulleys is mounted on each end of X-ray source tube housing 5 and iscoupled by drive gears. They drive gears and rotate X-ray source tubehousing 5 when the rotation driver is activated by software. A preferredspeed range of the X-ray tube housing 5 is from about 20 mm/s to about50 mm/s.

A pair of deflection electrical plates 7 is disposed to an arc of theX-ray source and an X-ray flat panel detector 1. The deflectionelectrical plates 7 are adjusted to a position where the X-ray sourceand the flat panel detector 1 are not in line. When the arcuate shape ispre-defined, and the X-ray source is mechanically moved in a circularmotion around its focal point in accordance with a speed control unitthat controls the speed of the primary motor 3 in conjunction with theX-ray exposure control unit that controls the time duration of the X-rayoutput from the X-ray source through trigger signal generated fromtrigger source, the X-ray source will trace out a curve in 3D space onthe detector. At the same time, the X-ray source will also race out acorresponding curve on the detector with some degree rotation in 3Dspace. Image data can be reconstructed with knowledge of the targetobject structure at each location that the X-ray source moves through.Knowledge of the target object geometry can be calculated withpre-measured landmarks and image processing tools to yield accurategeometric modeling of the interior body structures within the patient.One embodiment includes a two-dimensional or set of 3D cameras to detectpatient movement during the procedure and compensate for the patientmovement in real-time.

A supporting frame structure 2 provides housing for the X-ray sourcemoving mechanism. An arc rail, which can be part of a single axis motionstage, is provided to move along a circular track in one direction. Anelectronic controller (not shown) allows the speed of the arc rail to beprecisely controlled. A plurality of pulsed X-ray sources is mounted onthe moving mechanism in an array around the periphery of the arc rail.For the X-ray sources, any suitable type of X-ray tube may be used. Thearc rail and its related structure can be moved smoothly on thesupporting frame structure 2 at high speed and minimal friction. EachX-ray source is triggered when it comes into position relative to apatient during a sweep. Each X-ray source must be positioned so that thefocal spot of the X-ray source does not irradiate any portion of thepatient until the X-ray source is triggered.

In one embodiment, the system uses multiple pulsed X-ray sources inmotion to perform ultrafast, highly efficient 3D radiography. In thesystem, multiple pulsed X-ray sources are mounted on a structure inmotion to form an array of the source. The multiple X-ray sources movesimultaneously around an object on a pre-defined track at a constantspeed of a group. X-ray tube focal spot at each X-ray source can alsomove rapidly around its static position of a small distance bydeflection electrical field or deflection magnetic field. When an X-raytube focal spot on an individual X-ray source has a speed equal to groupspeed but an opposite moving direction, the respective X-ray source istriggered through an external exposure control unit. This arrangementallows the X-ray source to stay relatively standstill during the X-raypulse trigger exposure duration. Multiple X-ray sources result in amuch-reduced source travel distance for individual X-ray sources. X-rayreceptor is an X-ray flat panel detector 1. As a result, 3D radiographyimage projection data can be acquired with an overall much broader sweepin a much shorter time, and image analysis can also be done in real-timewhile the scan goes.

More details of the ultrafast 3D digital imaging system with multipulsed X-ray sources by deflecting tube electron beam 9 using deflectionmagnetic field is shown in FIG. 2 , which shows one of the multipleX-ray sources, each of which includes a pair of magnetic deflection coil8 are placed at an X-ray tube 6 inside an X-ray source tube housing 5.By applying current at the magnetic deflection coil 8, a magnetic fieldwill be created between the pair of the magnetic deflection coil 8. Thestrength of the magnetic field varies upon the current flow through themagnetic coil.

During operation, primary motor 3 engages primary stage 4 by gears toprovide motion for the X-ray sources in the housings 5. Primary motor 3can move primary stage 4 along the rigid rail at a predeterminedconstant speed. By applying current to a pair of magnetic deflectioncoils 8 at X-ray tube 6, X-ray tube electron beam 9 can be deflected byforce from the magnetic field before the electrons reach the X-ray tubetarget. By fine-tuning the current, the electron focal spot can movealong the direction of primary motor stage 4. When X-ray tube focalmoving speed is equal to the speed of primary motion stage 4 and has anopposite direction, then X-ray tube 6 and X-ray detector 1 aretriggered. At this trigger moment, X-ray tube 6 and X-ray detector 1actually have a relative standstill position.

The X-ray tube 6 is the heart of the X-ray machine. The X-ray tube 6 hashigh voltage terminals connected to an external high voltage powersupply through electrical wires. The X-ray tube 6 produces a currentflow along an electron gun column in a vacuum container inside the X-raytube 6.

A pair of magnetic deflection coils 8 is used to adjust the beams of theX-ray tube 6. The X-ray tube 6 or source could be a point source,smaller focal spot size is desirable. Smaller focal spot size would havebetter image resolution. A spectrally filtered X-ray tube is desirableto produce an X-ray beam of desired energy range. A tube-mount assemblyprovides an electrical and mechanical connection between the X-ray tube6 and the primary motor stage 4. Tube-mount assembly has a secondary ortertiary or more level of metal to shield against electricalinterference. A front and back cover and respectively could provideshielding against ambient radiation and airborne particles.

The X-ray source tube housing 5 with an X-ray tube 6 mounted inside ismoveable on the primary motor stage 4. The X-ray source tube housing 5is mounted at primary motor stage 4 that moves freely on an arc rail ata predetermined constant speed; a primary motor 3 that controls a speedof the primary motor stage 4; and multiple X-ray sources (one of whichis) housed in the X-ray source tube housing 5 that is all movedsimultaneously at the same speed as the primary motor stage 4. An X-rayflat panel detector 1 is to receive X-ray and send imaging data. It ismounted around the rotation center of the primary motor stage 4 toreceive the X-ray beam transmitted through a portion of the object undertest placed at the rotation center. An array of five X-ray sources ismounted on the X-ray source tube housing 5 at an equal angle to eachother; they move together with the primary motor stage 4 at a constantspeed. A collimator positioned between the X-ray source tube housing 5and the flat panel X-ray detector 1 along the axis of motion of theprimary motor stage 4 can limit the horizontal component of the X-raybeam passing through. A supporting frame structure 2 provides housingfor the primary motor stage 4 and an electrical field deflection devicesuch as a pair of deflection plates 7.

Primary motor 3 provides driving motion to move the primary motor stage4 on a predetermined track. A plurality of X-ray sources is mounted onthe primary motor stage 4 for emitting X-rays sequentially. The X-raysources are arranged in an array configuration, each X-ray source movingsimultaneously with the others on the primary motor stage along the samepath, at a constant speed and speed as a group. A flat panel detector 1is usually mounted on the supporting frame structure 2 to receive X-rayand send imaging data. A pair of electrical deflection plates 7 ormagnetic deflection coil 8 yoke is located in front of the X-ray tubetarget 11 to control the position of the X-ray source focal spot.Technical features of an X-ray imaging system using multiple pulsedX-ray sources in motion to perform ultrafast, highly efficient 3Dradiography: The first technical feature is that the primary motor stage4 is moved on a predetermined track. Each X-ray source is moved with theprimary motor stage 4 on the predetermined track, the X-ray sourcesmoving simultaneously with the others on the primary motor stage 4 alongthe same path, at a constant speed and speed as a group.

Primary motor stage 4 may be moved freely on an arc rail with apredetermined shape. A primary motor 3 that engages with the primarymotor stage 4 controls the speed of the primary motor stage 4. Incertain implementations, X-ray sources may be mounted on the primarymotor stage 4 and move simultaneously around an object on a pre-definedtrack at a constant speed of a group. X-ray tube focal spot at eachX-ray source can also move rapidly around its static position of a smalldistance by deflection electrical field or deflection magnetic field.When an X-ray tube focal spot on an individual X-ray source has a speedequal to group speed but an opposite moving direction, the respectiveX-ray source is triggered through an external exposure control unit.This arrangement allows the X-ray source to stay relatively standstillduring the X-ray pulse trigger exposure duration. Multiple X-ray sourcesresult in a much-reduced source travel distance for individual X-raysources. X-ray receptor is an X-ray flat panel detector 1. As a result,3D radiography image projection data can be acquired with an overallmuch broader sweep in a much shorter time, and image analysis can alsobe done in real-time while the scan goes.

Primary motion stage 4 is mounted on the fixed base structure of a frameand is placed so that it can move freely on an arc rail with apredetermined shape. A primary motor 3 drives the primary motor stage 4.The primary motor speed controller controls the speed of the primarymotor stage based on desired movement time and input from the computersystem (or programmed timing) during a scan. A power supply is connectedto the primary motor to provide electricity for primary motor operation.The primary motor stage 4 is a drive element that moves in a sweepingmotion along the rail of the base structure in the direction at aconstant speed, controlled by the primary motor 3. The center of theprimary motor stage 4 is a cylinder supporting an X-ray tube and a highvoltage generator.

X-ray flat panel detector 1 of an X-ray imaging system to provide fast3D radiography using multiple pulsed X-ray sources in motion with aprimary motor stage 4 moving freely on an arc rail with a predeterminedshape; a primary motor 3 that engages with said primary motor stage 4and controls a speed of the primary motor stage 4; a plurality of X-raysources each moved on the primary motor stage 4; a supporting framestructure 2 that provides housing for the primary motor stage 4; a flatpanel detector 1 to receive X-ray imaging data; a pair of deflectionplates 7 to produce electrical field or a pair of magnetic coil 8 yoketo produce a magnetic field at X-ray tube electron beam 9. A method offast 3D radiography using multiple pulsed X-ray sources in motionincludes positioning a primary motor stage 4 to a predetermined initiallocation; sweeping the primary motor stage at a predetermined constantspeed by said primary motor 3; deflecting X-ray tube electron beam 9with a predetermined sequence by applying a voltage to plate or byapplying current to magnetic coil 8; electrically activating an X-raysource and a flat panel detector when an X-ray tube focal spot moves inan opposite direction to that of the primary motor stage 4 and at aselected speed of the primary motor stage 4; and acquiring image datafrom a flat panel detector. In one embodiment, an X-ray imaging systemusing multiple pulsed X-ray sources in motion to perform ultrafast,highly efficient D radiography is presented.

FIG. 3 illustrates an exemplary complete X-ray exposure position. Inthis example, there are there are five X-ray tubes 6 in X-ray sourcetube housing 5, and the five X-ray tubes 6 at X-ray source tube housing5 perform 25 total X-ray exposures at different angle positions. Each ofthe five X-ray tubes 6 only needs to travel one-fifth of total coveredangle. Therefore, with multiple X-ray tubes 6 working in parallel, alarge amount of projection data can be acquired at a fraction of amountof time compared with that of a single X-ray source. An X-ray flat paneldetector 1 is served as an X-ray receiver. Electronic signal always goesfaster than that of mechanical motion, bottle neck of limiting factor isalways motor stage motion itself. Next bottleneck is detector readoutlimitation. Because detector also needs some time to read out many Megapixel data and then transfer to a computer.

In view of the widely available superfast computer available, imageanalysis can be done in real-time with the image acquisition. Judgmenton the images taken will have an impact on the X-ray tube 6 position forthe next shot. There is no need to wait until finish of whole imageacquisition to do image reconstruction. FIG. 3 illustrates that afive-X-ray-source system takes 25 sets of projection data by travelingonly one-fifth of the total distance. X-ray tubes 6 are a group ofmultiple pulsed X-ray sources to form an array of sources or multiplegroups of pulsed X-ray sources mounted on a structure in motion to forman array of sources. The multiple X-ray sources move simultaneouslyrelative to an object on a pre-defined arc track at a constant speed asa group. A focal spot at each X-ray source can also move rapidly aroundits static position at a small distance. When the X-ray tube focal spotof a respective X-ray source has a speed equal to group speed but anopposite moving direction, the X-ray source and an X-ray detector areactivated through an external exposure control unit.

This arrangement allows the X-ray source to stay relatively standstillduring the X-ray source activation and X-ray detector exposure. X-rayreceptor is an X-ray flat panel detector. The first advantage is thatsystem overall is several times faster. Each x-ray source would onlyneed to mechanically travel a small fraction of the whole distance in anarc trajectory. It greatly reduces the amount of data acquisition timeneeded for a patient at the X-ray diagnosis machine. The secondadvantage is that image analysis can also be done in real-time as thescan goes. Judgment on the images taken will impact the X-ray sourcefocal spot position for the next shot.

X-ray source tube housing 5 contains a primary X-ray tube 6 powered by ahigh voltage generator. In this patent, only one primary X-ray tubesource is described, but it should be understood that more than onesource may be used at the same time to acquire different parts of a 3Dimage data set. Primary X-ray tube housing 5 is mounted on a moveablestructure (not shown) with a motor control system to enable movement inany direction on an arc rail that forms a part of a circular arc trackor helical motion track around the patient. The high voltage generatoroutputs a high voltage electrical current that flows through powercables that go to the input connectors on the backside of the primaryX-ray tube. In addition, the X-ray source can have a separate voltagecontroller that can adjust the output voltage for both high voltageprimary X-ray tube and individual X-ray tube focal spot moving voltageto control the focal spot position around the static position.

Multiple X-ray tubes 6 are arranged in an array. The X-ray tubes 6 aremounted on a structure moved relative to the object by a primary motoron an arc rail in the exemplary embodiment. A sequence of moving thestructure of the X-ray tubes at a constant speed and a slight angle ispre-defined to generate an array of the X-ray tubes in motionsimultaneously around the object. At each time point, the direction ofthe movement of the X-ray tube, the distance between adjacent X-raytubes, and the time delay between adjacent X-ray tubes can be determinedto form an arc trajectory for all the X-ray tubes. At a certain timingpoint, each X-ray tube's focal spot (electron beam) is moved around itsstatic position by a predetermined electrical field or magnetic fieldfrom a deflection plate. A high voltage supply can produce a deflectionelectrical field at a pair of deflection plates that deflects the focalspot of the X-ray tube from its static position by a predetermineddistance to a new location that forms a predetermined geometric shape asillustrated in FIG. 5 .

X-ray flat panel detector 1 is used as a detector of an X-ray imagingsystem. X-ray flat panel detector 1 comprises a plurality of individualdetector panels arranged in two dimensions to form a square orrectangular shape and can be sensitive to X-rays. The X-ray flat paneldetector 1 is an ultra-high speed, high efficiency, active pixel sensorflat panel detector 1 with a fast readout capability. X-ray flat paneldetector 1 can provide images at frame rates higher than 25 fps. X-rayflat panel detector 1 includes each detector panel that can beindividually addressed for readout by address unit through panel driver.The X-ray tube 6 is located inside the X-ray machine with the X-ray tubefocal spot moved by deflection electrical field or deflection magneticfield from the X-ray controller. X-ray controller triggers X-ray tube 6activation bypassing trigger signal to the X-ray power supply.

A pair of magnetic deflection coils 8 are positioned near the X-ray tubein FIG. 4 . X-ray sources have a focal spot that can move by themagnetic field generated by coils and, respectively.

FIG. 4 illustrates an exemplary deflection of an electron beam in anX-ray tube can be deflected by magnetic coils 8 when current flowsthrough the coils. X-ray tube 6 can be fixed on a supporting frame orhave an electrically actuated mechanism to enable X-ray focal spotpositioning. In the latter case, the X-ray tube can move with a primarymotor stage 4 with the primary motor engaged to rotate a rotor shaft,thus controlling the speed of the primary motor stage 4. On the otherhand, a deflection plate is mounted to a platform at an equal distancefrom X-ray sources. The plate is part of a voltage/current drive systemthat can generate an electrical field or magnetic field. The plate isdriven by a control board that receives commands from the exposurecontrol unit via a digital interface. The voltage from the exposurecontrol unit passes through a converter to energize the electrical coilsof the magnetic coil, which generates a magnetic field surrounding theX-ray tube. An exposure control unit controls a magnetic coil through amagnetic coil driver. After starting a scan sequence, the control boardtriggers individual pulsed X-ray sources through a signal cable withdigital signals generated by the exposure control unit. Upon receiving atrigger command, respective pulsed X-ray sources begin a ramp-upoperation to increase power output.

In an embodiment, the X-ray source in the X-ray tube is stationary atthe beginning of the operation, but when it is time to expose the X-rayreceptor (flat panel detector), it moves in an opposite direction fromthe primary motor stage 4 while being fired with a selected speed. Inanother embodiment, the X-ray source can be turned on randomly bytriggering either from outside the system or from inside the systemusing a random firing scheme. Results of each and accumulated analysisdetermine the next X-ray source and exposure condition. 3D X-rayradiography images are reconstructed based on each image with an angledgeometry of the X-ray exposure source. Much broader applications include3D mammography or tomosynthesis, chest 3D radiography for COVID or fast3D IDT, fast 3D X-ray security inspection.

X-ray tube electron beam 9 and flat-panel detector 1 are positioned in aparallel arrangement to each other. X-ray tube focal spot moves aroundthe static position at a small distance on X-ray tube anode due tomagnetic field produced by magnetic coil yoke or electrical fieldproduced by deflector plates, depending on its design. At each instanceof X-ray tube focal spot's movement around its origin, the x-ray beamprojected onto a region of interest is determined by x-ray tube currentintensity that changes rapidly due to switching in a certain duration.The X-ray imaging system also includes a controlling unit with a randomfiring switch module (FFW) and exposure control unit (ECU) for operatingX-ray sources. The random firing switch module is connected to all X-raysources. It randomly fires one of the X-ray sources at a time with anexternally generated trigger signal. Thus, the activation of each X-raysource and image acquisition occurs simultaneously. When one of theX-ray sources is activated, an associated electronic unit that isconnected to a flat panel detector (units in total) will control theelectronic trigger signal applied to the flat panel detector so that theacquisition of x-ray imaging data begins simultaneously with theactivation of the X-ray source.

FIG. 5 illustrates an exemplary electron beam in an X-ray tubedeflection by electric plate pair through a voltage difference. X-raytube 6 has a focal spot with a finite size at an initial position thatchanges after an electrical field, or magnetic field has deflected theX-ray tube focal spot to a subsequent position. The multiple X-raysources are moved at the same speed as the primary motor stage butopposite to that of the primary motor stage on the predetermined track.They are also positioned relative to the first X-ray source and secondX-ray source at a selected angle relative to each other. In thisexample, four pulsed X-ray sources move simultaneously relative to theobject at a constant speed as a group and sequentially from one toanother as they sweep across the object. A corresponding detector ismounted on the opposite side of the primary motor stage 4 that isparallel to the movement direction of the pulsed X-ray sources.

Electrical deflection plate 7 is located between the X-ray tube cathodeand target. Electrical voltage pulses are applied to the electricaldeflection plate 7 to control the movement of the focal spot relative tothe X-ray source along a tracking axis, as shown in the schematicdiagram. The other electrical voltage pulses are applied to theelectrical deflection plate 7 to control the movement of the focal spotalong a direction perpendicular to the track axis, which results inmoving the focal spot back and forth along the track axis in synchronouswith other movements on track axis. The magnetic coil is mounted betweenthe X-ray tube cathode and target and is also used to control themovement of the focal spot. By applying different combinations ofelectrical or magnetic fields simultaneously to deflection device, theX-ray tube electron beam 9 is deflected along the moving direction ofprimary motor stage 4.

X-ray tube electron beam 9 has its focal spot moved around the x-raytube stationary axis by an external deflection electrical field (plate)or an external deflection magnetic field (coil). The focal spotconstantly moves as the primary motor stage 4 sweeps in a circular pathat a predetermined sweep speed to scan an object. This method is done inparallel with multiple X-ray sources.

X-ray tube cathode 10 produces the electron beam 9, and the X-ray isemitted after electron beam 9 hits X-ray tube target 11 and X-ray movingtoward the object is referred to as primary X-ray. The deflection coilsmay be located between the X-ray tube cathode 10 to deflect the electronbeam 9 toward the tube target 11 by passing an electrical currentthrough the deflection coils. A high voltage generator (the structurethat provides high voltage pulses) connected to the cathode produces anelectric pulse and sends it to the deflection coils to deflect theelectron beam 9 before it hits the target.

An X-ray tube 6 can include an electron gun, a heated cathode 10, X-raytube target 11 or other material that generates an electron beam 9 fromone end. X-ray tube target 11 is mounted on another end of the X-raytube 6. The electrical insulator and the material are attached to thehousing and conductive with the target. An electrical insulator can bemade of many different materials. Examples of electrical insulators caninclude Teflon and/or other dielectric materials such as glass or mica.Housing can be made of many different materials. Examples of housing caninclude stainless steel, aluminum, plastic, ceramic, combinationsthereof, or any other materials that will not interfere with thetransmission of X-rays. Electrical insulators and materials can have thesame or different compositions and can be configured in a single ormultiple layers between target and housing.

The primary motor stage 4 is mounted on a supporting frame structure 2that provides housing for the primary motor stage 4. An X-ray flat paneldetector 1 to receive X-ray flux is positioned to generate X-ray imageprojection data from the plurality of X-ray sources. The X-ray sourcesare arranged on a primary motor stage 4 that moves freely on an arc railwith a predetermined shape. An exposure control unit controls theelectrical field applied to each X-ray source to deflect the X-ray tubeelectron beam 9. An X-ray source moves simultaneously relative to anobject on a pre-defined track at a constant speed as a group. Each X-raysource focal spot can also move rapidly around its static position at asmall distance by deflection electrical field or deflection magneticfield. When an X-ray tube focal spot on an individual X-ray source has aspeed equal to group speed but an opposite moving direction, therespective X-ray source is triggered through an external exposurecontrol unit. Multiple pulsed X-ray sources result in a much-reducedsource travel distance for individual X-ray sources.

A primary motor stage 4 is positioned at a pre-defined initial locationand sweeps on an arc track at a constant speed by said primary motor.One or more X-ray sources each moved on the primary motor stage 4. Thepre-defined initial location can be set to any of various initiallocations depending on how one wishes to position a subject on the X-rayimaging machine for X-ray scanning. Various exemplary locations arechest X-ray scan (ventral/dorsal), chest CT scan, etc.

Various modifications and alterations of the invention will becomeapparent to those skilled in the art without departing from the spiritand scope of the invention, which is defined by the accompanying claims.It should be noted that steps recited in any method claims below do notnecessarily need to be performed in the order they are recited. Those ofordinary skill in the art will recognize variations in performing thesteps from the order in which they are recited. In addition, the lack ofmention or discussion of a feature, step, or component provides thebasis for claims where the absent feature or component is excluded byway of a proviso or similar claim language.

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only and not of limitation. The various diagrams may depict anexample architectural or other configuration for the invention, which isdone to understand the features and functionality that may be includedin the invention. The invention is not restricted to the illustratedexample architectures or configurations, but the desired features may beimplemented using various alternative architectures and configurations.Indeed, it will be apparent to one of skill in the art how alternativefunctional, logical, or physical partitioning and configurations may beimplemented to implement the desired features of the present invention.Also, many different constituent module names other than those depictedherein may be applied to the various partitions. Additionally, withregard to flow diagrams, operational descriptions, and method claims,the order in which the steps are presented herein shall not mandate thatvarious embodiments be implemented to perform the recited functionalityin the same order unless the context dictates otherwise.

Although the invention is described above in terms of various exemplaryembodiments and implementations, it should be understood that thevarious features, aspects, and functionality described in one or more ofthe individual embodiments are not limited in their applicability to theparticular embodiment with which they are described, but instead may beapplied, alone or in various combinations, to one or more of the otherembodiments of the invention, whether or not such embodiments aredescribed and whether or not such features are presented as being a partof a described embodiment. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open-ended as opposedto limiting. As examples of the previous, the term “including” should beread as meaning “including, without limitation” or the such as; the term“example” is used to provide exemplary instances of the item in thediscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or the suchas; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given period or to an item availableas of a given time. Instead, they should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Hence, where thisdocument refers to technologies that would be apparent or known to oneof ordinary skill in the art, such technologies encompass those apparentor known to the skilled artisan now or at any time in the future.

A group of items linked with the conjunction “and” should not be read asrequiring that every one of those items be present in the grouping, butrather should be read as “and/or” unless expressly stated otherwise.Similarly, a group of items linked with the conjunction “or” should notbe read as requiring mutual exclusivity among that group, but rathershould also be read as “and/or” unless expressly stated otherwise.Furthermore, although items, elements, or components of the inventionmay be described or claimed in the singular, the plural is contemplatedto be within the scope thereof unless limitation to the singular isexplicitly stated.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other such as phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. The use of theterm “module” does not imply that the components or functionalitydescribed or claimed as part of the module are all configured in acommon package. Indeed, any or all of the various components of amodule, whether control logic or other components, may be combined in asingle package or separately maintained and may further be distributedacross multiple locations.

Additionally, the various embodiments set forth herein are described inexemplary block diagrams, flow charts, and other illustrations. As willbecome apparent to one of ordinary skill in the art after reading thisdocument, the illustrated embodiments and their various alternatives maybe implemented without confinement to the illustrated examples. Forexample, block diagrams and their accompanying description should not beconstrued as mandating a particular architecture or configuration.

The previous description of the disclosed embodiments enables anyoneskilled in the art to make or use the present invention. Variousmodifications to these embodiments will be readily apparent to thoseskilled in the art. The generic principles defined herein may be appliedto other embodiments without departing from the spirit or scope of theinvention. Thus, the present invention is not intended to be limited tothe embodiments shown herein but is accorded the most comprehensivescope consistent with the principles and novel features disclosedherein.

While there has been shown several and alternate embodiments of thepresent invention, it is to be understood that certain changes can bemade as would be known to one skilled in the art without departing fromthe underlying scope of the invention as is discussed and set forthabove and below. Furthermore, the embodiments described above are onlyintended to illustrate the principles of the present invention. They arenot intended to limit the scope of the invention to the disclosedelements.

What is claimed is:
 1. A fast 3D radiography system comprising: aprimary motor stage moving freely on an arc rail; a primary motor thatengages with said primary motor stage and controls a speed of theprimary motor stage; a plurality of X-ray sources each mounted at theprimary motor stage; a supporting frame structure for the primary motorstage; and an x-ray flat panel detector.
 2. The system of claim 1,comprising a pair of electrical deflection plates on each X-ray tube ofX-ray source.
 3. The system of claim 1, comprising one or a pair ofmagnetic deflection coil yoke on each of X-ray tube of X-ray source. 4.The system of claim 1, wherein one or more of the x-ray sources isactivated using a predetermined scheme.
 5. The system of claim 1,wherein an initial spatial position of the primary motor stage isadjustable by software.
 6. The system of claim 1, wherein the result ofeach and accumulated analysis determines the next X-ray source andexposure condition.
 7. The system of claim 1, wherein exposure time ofX-ray source is adjustable by software.
 8. The system of claim 1,wherein the object is at a standstill.
 9. The system of claim 1, whereineach X-ray source comprises an X-ray tube focal spot and wherein theX-ray tube focal spot moves a small distance around a static position onX-ray tube target by deflection electrical field or deflection magneticfield.
 10. The system of claim 1, wherein each X-ray source comprises anX-ray tube focal spot and when the X-ray tube focal spot on anindividual X-ray source has a speed that equals to a group X-ray sourcespeed but an opposite moving direction, the individual X-ray source istriggered through an external exposure control unit, and wherein theX-ray source stays relatively standstill during the X-ray pulse triggerexposure duration.
 11. A method of fast 30 radiography comprising:positioning a primary motor stage driven by a primary motor; sweepingthe primary motor stage at a predetermined constant speed; deflectingX-ray tube electron beam with a predetermined sequence; electricallyactivating an X-ray source when an X-ray tube focal spot moves in theopposite direction to that of the primary motor stage and at a selectedspeed of the primary motor stage; and acquiring image data from theX-ray flat panel detector.
 12. The method of claim 11, comprisingproviding a pair of electrical deflection plates on each X-ray tube ofX-ray source.
 13. The method of claim 11, comprising providing one or apair of deflection magnetic coil yoke on each of X-ray tube of X-raysource.
 14. The method of claim 11, wherein 4D imaging is performed byadding a time component to 3D spatial imaging data.
 15. The method ofclaim 11, comprising changing a sweep angle based on a region ofinterest.
 16. The method of claim 11, wherein X-ray imaging data isacquired and reconstructed in real- time to determine the next X-raysource and exposure condition.
 17. The method of claim 11, comprisingchanging an X-ray source voltage input based on object density during asweep.
 18. The method of claim 11, wherein the x-ray flat panel detector1 s coupled to a linear stage to adjust a position based on locations ofX-ray sources.
 19. The method of claim 11, wherein each X-ray sourcecomprises an X-ray tube focal spot and wherein the X-ray tube focal spotmoves a small distance around a static position on X-ray tube target bydeflection electrical field or deflection magnetic field.
 20. The methodof claim 11, wherein each X-ray source comprises an X-ray tube focalspot and when the X-ray tube focal spot on an individual X-ray sourcehas a speed that equals to a group X-ray source speed but an oppositemoving direction, the individual X-ray source is triggered through anexternal exposure control unit, and wherein the X-ray source staysrelatively standstill during the X-ray pulse trigger exposure duration.